This invention generally relates to examining devices such as laryngoscopes and particularly to an improved system to connect the blade to the handle of a laryngoscope.
Laryngoscopes generally comprise a blade and a cooperating handle which are connected together in a generally L-shaped configuration. The handle normally serves as an enclosure for one or more batteries which energize a light bulb secured adjacent to the blade and connected by wires or other electrical conducting means to the batteries in the handle. The switch for activating the light bulb is usually positioned immediately adjacent to the light bulb and is operated by the blade when it is connected to on the handle. The light from the bulb passes through a clear light conductor to the distal end of the blade to illuminate the patient's mouth and larynx during the examination thereof by medical personnel. The surface on the blade adjacent to the handle is used to press against the tongue and mandible of a patient in a supine position in order to prevent the patient's tongue from obstructing the visual examination of the larynx by medical personnel.
While the instrument is useful for examining the larynx, the primary function of the laryngoscope is to expose the larynx in order to facilitate the insertion of an endotracheal tube. The surface of the laryngoscope blade adjacent the handle is urged against the tongue and mandible to expose the larynx in such procedures and the opposite blade surface is positioned opposing the upper front teeth of the patient.
When using the laryngoscope there is a tendency to use the upper front teeth of the patient as a fulcrum for the blade in exposing the larynx and in order to minimize damage to the patient's front teeth that portion of the blade which comes in contact with the patient's front teeth is is made to yield when pressed against the patient's teeth to avoid chipping or breaking the teeth.
In many of the laryngoscopes in use today, the switch which turns on the light bulb is actuated when the blade is connected to the handle. To turn the light off the blade must be disengaged from the handle. However, it is frequently desirable to connect the blade to the handle without actuating the lighting means and moreover it is frequently desirable to turn the light off without disengaging the blade from the handle.
In many of the prior art laryngoscopes, the means for connecting the blade to the handle generally comprises a depending appendage at the proximal end of the blade generally in the shape of a boot. The appendage fits into an open channel on the top of the handle and the front end of the boot-shaped appendage hooks under a pivot rod at the front end of the channel. Ball detents are provided in the depending section of the blade which snap into position in the dimples provided in the walls of the channel to thereby fix the position of the blade with respect to the handle. If the ball detents become disengaged from the dimples, then the blade is readily disconnected from the handle. For the medical personnel, usually anesthesiologists, who utilize the laryngoscopes, this frequently poses a problem inasmuch as if the device needs to be used again, both hands must then be available to reconnect the blade to the handle and snap the blade into position to actuate the lighting means.
The present invention provides an improved means to connect the blade to the handle of laryngoscope which resolves many of the aforesaid problems of the prior devices.